Abstract

In modern launch vehicles, the unsteady aerodynamic forces caused by flow separation during the transonic regime induce aeroelastic instabilities like buffeting, which may lead to structural failure. Quantifying the buffet loads in the critical transonic regime is important to ensure the safety of the vehicle structure. The complexity of the buffeting phenomena makes the computational effort ifficult to predict the aerodynamic-elastic-inertial interactions. Hence the designer has to employ experimental approach to evaluate the necessary aeroelastic characteristics of launch vehicles. This paper presents a case study of experimental aeroelastic studies on gsLVM3 launch vehicle. For this an aerodynamically shaped and dynamically scaled model is designed, fabricated and wind tunnel tested. The responses of the mounted sensors on the model have been acquired during the tunnel testing and analyzed. The transonic buffet experienced by the model has been presented in the form of dynamic bending moment for different flight conditions. Finally, the critical buffet loads for the full scale vehicle are obtained using appropriate scale factor.